1. Field of the Invention
This invention relates in general to semiconductor devices and more specifically to fuses for semiconductor devices.
2. Description of the Related Art
Programmable fuses are utilized in semiconductor devices e.g. for chip identification, circuit customization, and memory repair. With some types of fuses, a programming structure electrically couples two conductive structures. To electrically program the fuse, a current is driven between the conductive structures to heat the programming structure wherein the conductive programming structure becomes physically discontinuous or the material of the conductive programming structures becomes discontinuous. Accordingly, for a programmed fuse exhibiting a high impedance state, the two conductive structures have a high resistance or have an open circuit between them.
One problem with electrically programming a fuse is that it is desirable to contain the heat generated from programming to the fuse area of an integrated circuit so as not to damage other portions of the integrated circuit. Also, it is desirable to contain the heat within the region of the programming structure to more efficiently make discontinuous the programming structure, thereby requiring less current to program the structure.
Typically, dielectric structures (e.g. silicon oxide) are used as a thermally insulative material to keep the programming heat from diffusing from other parts of the integrated circuit. However, the formation of these dielectric structures may require extra processing steps.
What is needed is an improved electrically programmable fuse.
The use of the same reference symbols in different drawings indicates identical items unless otherwise noted. The features shown in the Figures are not necessarily drawn to scale.